Machine foe bending metal baks



(No Model.) 3 Sheets-Sheet 1.,

T. P. KRUG.

MACHINE FOR BENDING METAL BARS.

' I Patented Aug. 27 1889.

1 Eli,

WITNESSES: INVENTOR:

ATTORNEY.

(No Model.) 3 Sheets-Sheet 2.

T. F. KRUG. MACHINE FOR BENDING METAL BARS.

No. 410,112. Patented Aug. 27 1889.

WITNESSES INVENTOR:

tam 5 71 Wmw My ATTORNEY.

' (No Model.) 3 Sheets-Sheet 3.

T. P. KRUG. MAGHINE FOR BENDING METAL BARS.

No. 410,112. r .v Pate%1ted'Aug.Z7 1 889.

INVENTOR:

JMQJGW BY CAM ATTORNEY.

WITNESSES: .N

N PETERS. Pmmmm m. Washington. 0. c.

UNITED STATES THEODORE F. KRUG, OF BALTIMORE,

MARYLAND, ASSIGNOR TO G. KRUG &

SON, OF SAME PLACE.

MACHINE FOR BENDING METAL BARS.

SPECIFICATION forming part of Letters Patent No. 41Q,112, dated August27, 1889.

Serial No. 305,851. (No model.)

To ctZZ whom it may concern.-

Be it known that I, THEODORE F. KBUG, a citizen of the United States,residing at Baltimore, in the State of Maryland, have invented certainnew and useful Improvements in Machines for Forming Metal Timber-Hangers, of which the following is a specifiation.

This invention relates to a machine for bending metal bars, and in thepresent instance is shown as adapted to make stirrups or timber-hangerssuch as are usedin the construction of houses and for other purposes.

The invention is illustrated in the accompanying drawings, in which-Figurelisatop view of part of the machine. Fig.2 is a cross-section onthe line 2 2. Figs.

3 and 4 are views of the metal bar before thestirrup .is formed. Fig. 5is a view of a finished stirrup. Fig. 6 is a cross-section of part 3 ofthe machine on the line 6 6. Fig. 7 is a view of the eccentric-shaft.Fig. 8 is a view of the slide-jaw. Fig. 9 is a side view of the machine.Figs. 10 and 11 are views of the center-bending device. p

The main iron block A is mounted and centrally pivoted on a base B. Apivot-shaft O connects the block and base, and the arrangement is suchthat the said main block may tiltdown on either side, thereby elevatingone side or the other, as may bedesired. The two opposite sides a of theblock are beveled or inclined from the top facet, and each beveled sideis provided with one or more crossledges a, cast integral with theblock. The cross'ledge is in line with the grip device hereinafterdescribed and serves as a side support for the metal bar while its endis being bent. This main block is provided in its top face I) with oneor more grooved slideways d, and each slideway has a movable grip-j awE,which is confined by the side plates 1). The endf of each groovedslideway forms one side of a clamp or grip, of which the end f of theslidejaw E forms the other. A clamp or grip of this kind is at both endsof the slide-jaw. As shown in Figs. 1 and 6, the main block in thepresent instance has three slide-jawsE, each of a different length fromthe other. These clamps or grips are to receive the end 9 of the metalbar that is to be bent. An

opening or hole It is made through the main before bending, is shown inFig. 3. Thebar has a twist t, which is imparted to it previous to itsreceiving any treatment by the machine. The end 9 of the bar is to enterone of the grips ff, as shown in Fig. 2, and is then bent to form theangle j, and again bent down to form the second angle j. This latterangle is formed by bending the bar over the edge 7' of the main block,at which time the crossledge 0 serves as a side supportfor thehangerpart c of the bar The edge of the said hanger part c of the bar restsupon the beveled or inclined side a of the block, and thereby the hangerpart of the bar has imparted to it-ja corresponding inclination from thehook part. Each slide-jaw E is moved endwise by a square-headedeccentric-shaft F. The lower end is of each eccentric-shaft fits andturns in a bearing Z in the block A, and the upper part end. Theslide-jaw E has a rectangular hole loosely occupies this recess and ismovable laterally or crosswise of the jaw, but not lengthwise. Theeccentric part m of the shaft F occupies a round hole in the -movableblock 0.

Itwill be seen that by partly turning the eccentric-shaft the slide-j awE will be moved endwise in the grooved slideway d, andthereby the gripff will be closed and opened. It is intended that each end of theslide-jaw E will serve as a gripper.

A washer-plate p rests on and covers the block 0 and recess n and keepsiron-scale from entering the recess.

To turn'the eccentric-shaft F, a crank-arm G is applied to the squarehead. A quarterturn is sufficient. When the crank-arm is moved from theposition shown in Fig. 1 to the down position shown in Fig. 9, whichlatter is the operative or gripping position, a weight 0 on the end ofthe crank-arm Gserves to hold it from moving when in the down position.(Shown in Fig. 9.)

At each corner of the main block A is a hook g, which projects -abovethe top face.

block below each grip and affords escape for the scale that drops fromthe heated end of the said metal bar. The metal bar I, as it appears mof said shaft is eccentric with the said lower or recess 02, (see Figs.6 and 8,) and a block 0- bar, (not shown,) while the other end is heldby an attendant. A straight bar with one end under the said hook q willthus serve to confine the heated bar close to the top face I) while thesecond angle j is beingbent. The two ends of the barI are bentseparately, one at a time, the center bends s 3 being made last. Whenthe two angles jj are bent on one end of the metal bar I, it isnecessary to operate at one side of the main block, and it is moreconvenient to tilt the block so as to raise one side, and the operatingside must be the high side, as shown in Fig. 9. When bending the twoangles jj on the other end of the metal bar, it is necessary to tilt theblock the opposite way, so as to bring the other side up. It is thusintended to employ the two opposite beveled sides of the block.

This necessity for working on two sides of the block arises from thefact that the twistt' at one end of the barI is in a different directionfrom the twist at the other end.

The bar has two central bends or angles 3, which are formed by thedevice shown in Figs. 10 and 11. The plate L has a seat 2%, for theformer s, which is secured thereto by bolts u, and thereby the formermaybe readily removed to admit another of different size. At each sideof the plate is arigid arm N, secured by bolts 0, and each has a gagedevice P and a set-screw o, whereby the gage is adjustablelongitudinally on the arm. The gage P serves as a stop against which thehook part j j at one end of the stirrup abuts, and said stop or gagedetermines where the bends or angles 3 of the bar will come. Twopivot-holes w are at each side of the plate, and two bending levers Qare employed. Each has a pin 10, which fits in either one or the otherof said pivot-holes. The movement of the bending-levers (only one isshown in the drawings) is indicated in Fig. 11 by a curved broken lin e.

A presser-clamp R is movable toward and away from the end of the formers by a screw 00, which turns in a fixed nut and hearing y, secured tothe plate L. A crank arm or wrench (not shown) must be applied to thesquare end cc of the screw, in order to turn it.

The operation of the center-bender is as follows: The bar I, with bothends bent to form the end hooks, is placed crosswise of the plate L atthe end of the former s, so that the gage device P will determine itsproper position. The screw x is then turned to bring the presser-clamp Rtight against the center of the bar I and hold it fast against the endof the former s. The two ends of block loosely occupying said hole orrecess,

and a shaft fitted to turn in the main block and having an eccentric endwhich turns in the said loose block.

2. 111 a machine for bending metal bars, the combination of a block A,provided with a grooved slideway and having on its side a cross-ledge c,a gripjaw movable in said slideway, and an eccentric to move saidgripjaw.

3. In a machine for bending metal bars, the combination of a block A,provided with a grooved slideway having stop ends f, which are solid orintegral with the block and form one side of a grip, a jaw movable insaid slideway and constituting the other side of the grip, an eccentricwhose shaft has a hearing in said block and moves the sliding gripjaw, acrank-arm to turn the eccentric-shaft, and a weight 1" to hold the shaftin position, as set forth.

4. In a machine forbending metal bars, the combination of a block A,provided with a grooved slideway and having at the corner a hook (1,which projects above the top, and having on its side a cross-ledge c, agrip-jaw movable in said slideway, and an eccentric to move'saidgrip-jaw.

5. In a machine for bending metal bars, the combination of a block A,provided with a slide-jaw, each end of which forms one side of a grip, abase, and a pivot connecting the block and base.

6. In a machine for bending metal bars, the combination of a block A,provided with two opposite beveled-or inclined sides, and a slidejaw,each end of which forms one side of a grip.

In testimony whereof I affix my signature in the presence of twowitnesses.

THEODORE F. KRUG.

Witnesses:

JNo. T. MADDoX, JOHN E. MORRIS.

